Hello
I'm trying to diagnose a problem I have with my own hand-soldered nRF51822-QFAA based bluetooth proximity device. I have the PCA10028 development kit to compare with using a low end oscilloscope but unfortunately no spec an.
The device works fine running non-soft device PWM example (and others) but if for example I run the heart rate example with softdevice (ble_app_hrs_s110 with custom board header), I am unable to see device with my phone.
The device is clearly entering advertising mode as my assigned onboard LED is blinking according to the example and I see a 5Hz repetition of VDD_PA producing 3x 1.8V pulses at 1kHz. The HF osc as measured at C1X1 junction looks to be struggling to start as compared to the clean 16MHz produced on the PCA10028. Also the PCA10028 VDD_PA occasionally shows a 4th slightly narrower pulse.
my PCB VDD_PA
my PCB C1X1 junction
PCA10028 VDD_PA #1
PCA10028 VDD_PA #2
PCA10028 C1X1 junction
Running the transmitter example shows that the oscillator appears to work on both my PCB and PCA10028:
my PCB C1X1 junction running transmitter example
PCA10028 C1X1 junction running transmitter example
So I am a bit confused. It appears my HF oscillator might be too slow starting or is something else the cause?
Regards m
